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The subprocess module defines one class, Popen and a few wrapper functions that use that class. The constructor for Popen takes arguments to set up the new process so the parent can communicate with it via pipes. It provides all of the functionality of the other modules and functions it replaces, and more.
Python Subprocess Example Subprocess comes with more than just the call method; it includes the Popen() method. The Popen method does not wait for the subprocess to end before returning information. To do this with Popen, you must use the wait() method after Popen.
The main difference is that subprocess. run() executes a command and waits for it to finish, while with subprocess. Popen you can continue doing your stuff while the process finishes and then just repeatedly call Popen. communicate() yourself to pass and receive data to your process.
Popen do we need to close the connection or subprocess automatically closes the connection? Usually, the examples in the official documentation are complete. There the connection is not closed. So you do not need to close most probably.
I'm having a problem with subprocess.Popen when args parameter is given as sequence.
For example:
import subprocess
maildir = "/home/support/Maildir"
This works (it prints the correct size of /home/support/Maildir dir):
size = subprocess.Popen(["du -s -b " + maildir], shell=True,
stdout=subprocess.PIPE).communicate()[0].split()[0]
print size
But, this doesn't work (try it):
size = subprocess.Popen(["du", "-s -b", maildir], shell=True,
stdout=subprocess.PIPE).communicate()[0].split()[0]
print size
What's wrong?
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